Bioanalytics or bioanalysis is the analysis of biological samples. Bioanalysis systems often use light to excite fluorescence from molecular tags in a sample (referred to herein as fluorescent tags or fluors). Fluors may be exogenous, as in the case of fluorescently labeled immunochemical tags that recognize subcellular structure and bind to impose fluorescent labeling; or endogenous, as in the case of genetically modified cells in which fluorescent proteins for example are expressed in order to impart specific fluorescent signals within a living cell. Particularly in fields such as fluorescence imaging, gene expression analysis, various types of sequencing, high resolution fluorescence microscopy, fluorescence life time measurements, and high content screening, it is necessary to be able to measure the amount of fluorescence and compare that amount to other measurements. This means the excitation light flux must generally be measured for each illumination exposure or fluorescence excitation event. To monitor biological events, it is necessary to be able to measure specific biological activity with often sub-millisecond exposure times. Excitation and detection must occur rapidly, such that the illumination must be generally switched on and off within a time period that is at most one-tenth of the duration of the minimum exposure time. Additionally, fluors can be temporarily or permanently photo-bleached, and biological samples can be otherwise damaged by the illumination light—a process known as phototoxicity. In order to minimize perturbation of the fluors due to photo-bleaching, and photo-damage to the biological samples, it is generally desired to minimize the light flux or dosage within the constraints of the signal-to-noise (S/N) requirements of that particular bioanalysis system. These are the general areas that embodiments of the invention are intended to address.